There are plenty of big questions still unanswered on
"Marvel's Agents of SHIELD," but the biggest is the identity of the Clairvoyant. Considering the most recent episode,
"Yes Men," seemed to imply that Melinda May is working for this mysterious entity, the threat of the Clairvoyant has never hit closer to home.

Because of the nature of "Agents of SHIELD," the theories of who the Clairvoyant is have ranged from Agent Coulson himself to Loki. While chatting with the cast of the ABC series at PaleyFest, they revealed to
Zap2it what their favorite theories are.

Co-showrunner Jed Whedon says, "We've had all sorts of theories. Every single cast member has been put forward in one theory or another."

Maurissa Tancharoen adds, "And there was a while where every cast member was like, 'I bet I know who it is -- it's me.'"

At least one of the cast members guessed correctly when they speculated the Clairvoyant's identity. Iain De Caestecker proudly revealed he figured it out before the rest of the cast. "I was right," he says. "Not in all the details, but I pieced it together."

"Iain called it. Not all the details right though," Elizabeth Henstridge acknowledges. "We all had different theories on the show, I feel like, and I was 100 percent wrong. The way that it turns out, I don't think anyone saw it coming."

Chloe Bennet admits that it's hard to think of the theories put forth before now that the identity has been revealed to the cast. "It's hard to think of the theories knowing who it is, or what it is, or whatever," she says. "They're all really interesting and great ideas."

The other big mystery on the show is who -- or what -- is the blue creature Coulson found in TAHITI.

"I know more than you, and less than I want to know," Gregg says. "I know it's not a Smurf. I've got a feeling it's not a Frost Giant. There was a lot of blue races that Coulson recently asked Lady Sif about, and I would surprised if it didn't turn out to be one of those. She knows a lot, that Lady Sif."

Just don't expect all of that storyline to be resolved in Season 1. "We'll find out a little more," Whedon says. "And as we answer questions, we ask new ones."

"Things will start to trickle out," Tancharoen says. "You'll see as we reach the end of the season, we're definitely teeing something up for Season 2."